Effect of summer environment on growing lambs under hot semi-arid tropical region

Abstract

Extended hot summer is a major constrain in animal production in the semi-arid tropical region. However, the adult native sheep is well-adapted to this climatic condition. Nonetheless, the adaptability of growing lambs in summer conditions is yet to be explored for sustainable sheep production. Therefore, the present study was carried out to assess the effect of summer environment on the growing lambs under hot semi-arid region. For this purpose, sixteen Malpura weaner lambs of 3-4 months of age were selected and equally distributed into two groups, viz. C and T. The lambs of T groups were kept inside the psychometric chamber in different temperature and humidity schedules simulated with the summer average temperature and humidity of the last 10-year of the semi-arid tropics. The lambs of C groups were kept inside the pen in a thermocomfort environment with the same space availability of T group lambs. The lambs of both the groups were provided with adlibitum feed and water. The water intake, respiration rate (RR), pulse rate (PR), rectal temperature (RT) and skin temperature of T group lamb was significantly (P<0.05) higher as compared to C group lambs. The summer exposure (T) reduced (P<0.01) the feeding and rumination time whereas increased (P<0.01) the panting in lambs as compared to C group. The endocrine profile did not varied (P>0.05) with the simulated summer exposure of semi-arid region in lambs. The present study reflected that the native Malpura growing lamb modifies their behavior and thermoregulatory responses to counter the extreme summer of the semi-arid region.